What version of MySQL are you running. Frequent Corruption seemed to be an issue for sure in 4.0.12 I think. But it was fixed with MySQL 4.0.13. I think there was an underlying issue in earlier versions of MySQL. Wasn't really a threads issue though.
If it's a MySQL issue you're having.... you'd have it with VB as well as it also uses MySQL.
If you're on your own server, I'd recommend a professional tuning MySQL. Jeremy also posted some good "how to" stuff on getting this done here in the MySQL forum.
